Considering his size and weight he is the P4P slickest boxer in history. Vitali only has 2 fights where he was hit with anything significant and that is amazing considering that he reigned as HW champion for almost half of his career. This isn't to discredit his chin that is iron, but his slickness has prevented most to hit that chin.
He is not slick at all man P4P... have you heard of guys like Willie Pep? maybe Pernell Whitaker P4P they're whats considered slick Vitali is no where near slick For him th be one of the best slickstrs he'd have to be as slick as them in a heavyweight version which he is not in no way shape or form